Apparatus for cutting filamentary material

Abstract

A modification to a reel type staple cutter that includes a housing surrounding the cutter reel. The housing has a cam slot sized to permit passage of a single tow but to prevent passage of a knot tieing together two ends of tow. As the cutter turns the knot slides along the outside of the slot reaching the top of the housing. The knot remains on top of the housing until the ends of the knot are cut. Means are provided to remove the knot.

I claim: 
     
       1. In an apparatus for cutting tow into predetermined lengths including a frame, a driven cutting reel rotatable in said frame for receiving successive wrappings of tow moving in a path toward the reel to be cut, an apparatus for removing knots formed by tieing the ends of two single tows together said apparatus comprising: a housing attached to said frame, said housing surrounding said reel, and having a continuous upstanding side wall and a top attached to the wall, said side wall and said top having a cam slot formed therein, said slot being sized to permit passage of a single tow, but to prevent passage of a knot, said cam slot having one end in alignment with said path and the other end of the slot terminating on the top of the housing; and means for removing the knot when the ends are cut by the reel. 
     
     
       2. The apparatus of claim 1, wherein said means for removing the knot when its ends are cut comprises: an arm pivotally mounted to said frame for back and forth movement across said slot in said top; a slotted foot attached to one end of said arm for engaging said knot; means for moving said arm; and a linkage coupling the other end of said arm and said means for moving the arm. 
     
     
       3. The aparatus for claim 1, wherein said means for removing said knot is a source of vacuum adjacent the location of the knot. 
     
     
       4. The apparatus of claim 1 including a deflector to deflect said knot from said path to the side wall of the housing and to guide the tow into said cam slot in the side wall of the housing. 
     
     
       5. A method for continuously cutting tow into predetermined lengths comprising the steps of: (a) feeding one end of a first tow into the cutter reel of a staple cutter for cutting the tow into predetermined lengths; (b) supplying one end of a second tow adjacent to the other end of said first tow; (c) tying said one end of said second tow and said other end of said first tow into a knot; (d) excluding said knot from said cutter reel while allowing said one end of said second tow to become wrapped on said cutter reel; (e) cutting said other end of said first tow and said one end of said second tow by means of said cutter reel; (f) removing said knot; and (g) repeating steps (a) through (f).